Fluid Attacks Database

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Component	Affected version	Patched versions
debian 12	pypdf	=3.17.4-1 \|\| =3.4.1-1 \|\| =3.4.1-1+deb12u1 \|\| =4.0.0-1 \|\| =4.0.0-1~exp1 \|\| =4.0.1-1 \|\| =4.0.2-1 \|\| =4.1.0-1 \|\| =4.2.0-1 \|\| =4.3.1-1 \|\| =5.4.0-1 \|\| =6.9.0-1 \|\| =6.9.2-1 \|\| =6.9.2-2	-
pypi	pypdf	>=0 <6.7.1	6.7.1
debian 13	pypdf	=5.4.0-1 \|\| =6.9.0-1 \|\| =6.9.2-1 \|\| =6.9.2-2	-
debian 14	pypdf	=5.4.0-1 \|\| >=0 <6.9.0-1	6.9.0-1
debian 12	pypdf2	=2.12.1-3 \|\| =2.12.1-3+deb12u1 \|\| =2.12.1-4	-

Aliases

1. CVE-2026-270262. NVD-2026-270263. OSV-DEBIAN-2026-270264. OSV-2026-270265. GHSA-9mvc-8737-8j8h6. GCVE-2026-270267. SECURITY-TRACKER-CVE-2026-27026

References

1. https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h2. https://github.com/py-pdf/pypdf/pull/36443. https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad802770164. https://github.com/py-pdf/pypdf/releases/tag/6.7.1

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